The off-label sales allegedly constituted a majority of the drug's revenues at the time, and once the FDA told Gilead to stick to the rules, Gilead's stock plunged -- triggering the suit by aggrieved shareholders. The fact that Gilead was seeking approval for the previously off-label condition puts the company in the bizarre position of having to argue that it did not believe Viread should be used for hep B, even though it wanted the FDA to approve Viread for hep B -- and from now will be legally promoting Viread for hep B.

And the extra revenues Gilead will earn from being able to revivify the Viread franchise could be offset by any award for the plaintiffs in the California suit. Gilead has thus far had nothing to say about the ruling.